This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Membrane proteins are of particular interest in proteomics because of their potential therapeutic utility. However, most of membrane proteins, especially integral membrane proteins (IMPs) are difficult to analyze due to their high hydrophobicity and low abundance. For the successful characterization of IMPs, we have developed the MS based strategy for membrane protein analysis.